Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvement and fixes from Arnaldo Carvalho de Melo:

User visible changes:

  - Add new compaction-times python script. (Tony Jones)

  - Make the --[no-]-demangle/--[no-]-demangle-kernel command line
    options available in 'perf script' too. (Mark Drayton)

  - Allow for negative numbers in libtraceevent's print format,
    fixing up misformatting in some tracepoints. (Steven Rostedt)

Infrastructure changes:

  - perf_env/perf_evlist changes to allow accessing the data
    structure with the environment where some perf data was
    collected in functions not necessarily related to perf.data
    file processing. (Kan Liang)

  - Cleanups for the tracepoint definition location paths routines. (Jiri Olsa)

  - Introduce sysfs/filename__sprintf_build_id, removing code
    duplication. (Masami Hiramatsu)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

29 files changed, 433 insertions, 102 deletions

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 5c1867a..4d88593 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4828,6 +4828,7 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct event
 			case 'z':
 			case 'Z':
 			case '0' ... '9':
+			case '-':
 				goto cont_process;
 			case 'p':
 				if (pevent->long_size == 4)
diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index c0d2479..614b2c7 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -226,6 +226,13 @@ OPTIONS
 	Display context switch events i.e. events of type PERF_RECORD_SWITCH or
 	PERF_RECORD_SWITCH_CPU_WIDE.
 
+--demangle::
+	Demangle symbol names to human readable form. It's enabled by default,
+	disable with --no-demangle.
+
+--demangle-kernel::
+	Demangle kernel symbol names to human readable form (for C++ kernels).
+
 --header
 	Show perf.data header.
 
diff --git a/tools/perf/arch/common.c b/tools/perf/arch/common.c
index b7bb42c..b00dfd92 100644
--- a/tools/perf/arch/common.c
+++ b/tools/perf/arch/common.c
@@ -128,7 +128,7 @@ static const char *normalize_arch(char *arch)
 	return arch;
 }
 
-static int perf_session_env__lookup_binutils_path(struct perf_session_env *env,
+static int perf_session_env__lookup_binutils_path(struct perf_env *env,
 						  const char *name,
 						  const char **path)
 {
@@ -206,7 +206,7 @@ out_error:
 	return -1;
 }
 
-int perf_session_env__lookup_objdump(struct perf_session_env *env)
+int perf_session_env__lookup_objdump(struct perf_env *env)
 {
 	/*
 	 * For live mode, env->arch will be NULL and we can use
diff --git a/tools/perf/arch/common.h b/tools/perf/arch/common.h
index ede246e..20176df 100644
--- a/tools/perf/arch/common.h
+++ b/tools/perf/arch/common.h
@@ -5,6 +5,6 @@
 
 extern const char *objdump_path;
 
-int perf_session_env__lookup_objdump(struct perf_session_env *env);
+int perf_session_env__lookup_objdump(struct perf_env *env);
 
 #endif /* ARCH_PERF_COMMON_H */
diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index 65b4835..7b8450c 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -25,8 +25,6 @@
 static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
 {
 	char root_dir[PATH_MAX];
-	char notes[PATH_MAX];
-	u8 build_id[BUILD_ID_SIZE];
 	char *p;
 
 	strlcpy(root_dir, proc_dir, sizeof(root_dir));
@@ -35,15 +33,7 @@ static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
 	if (!p)
 		return -1;
 	*p = '\0';
-
-	scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
-
-	if (sysfs__read_build_id(notes, build_id, sizeof(build_id)))
-		return -1;
-
-	build_id__sprintf(build_id, sizeof(build_id), sbuildid);
-
-	return 0;
+	return sysfs__sprintf_build_id(root_dir, sbuildid);
 }
 
 static int build_id_cache__kcore_dir(char *dir, size_t sz)
@@ -138,7 +128,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 		return -1;
 	*p = '\0';
 
-	if (build_id_cache__kcore_buildid(from_dir, sbuildid))
+	if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
 		return -1;
 
 	scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s",
diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
index b5ca988..918b4de 100644
--- a/tools/perf/builtin-buildid-list.c
+++ b/tools/perf/builtin-buildid-list.c
@@ -19,29 +19,25 @@
 
 static int sysfs__fprintf_build_id(FILE *fp)
 {
-	u8 kallsyms_build_id[BUILD_ID_SIZE];
 	char sbuild_id[SBUILD_ID_SIZE];
+	int ret;
 
-	if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
-				 sizeof(kallsyms_build_id)) != 0)
-		return -1;
+	ret = sysfs__sprintf_build_id("/", sbuild_id);
+	if (ret != sizeof(sbuild_id))
+		return ret < 0 ? ret : -EINVAL;
 
-	build_id__sprintf(kallsyms_build_id, sizeof(kallsyms_build_id),
-			  sbuild_id);
-	fprintf(fp, "%s\n", sbuild_id);
-	return 0;
+	return fprintf(fp, "%s\n", sbuild_id);
 }
 
 static int filename__fprintf_build_id(const char *name, FILE *fp)
 {
-	u8 build_id[BUILD_ID_SIZE];
 	char sbuild_id[SBUILD_ID_SIZE];
+	int ret;
 
-	if (filename__read_build_id(name, build_id,
-				    sizeof(build_id)) != sizeof(build_id))
-		return 0;
+	ret = filename__sprintf_build_id(name, sbuild_id);
+	if (ret != sizeof(sbuild_id))
+		return ret < 0 ? ret : -EINVAL;
 
-	build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
 	return fprintf(fp, "%s\n", sbuild_id);
 }
 
@@ -63,7 +59,7 @@ static int perf_session__list_build_ids(bool force, bool with_hits)
 	/*
 	 * See if this is an ELF file first:
 	 */
-	if (filename__fprintf_build_id(input_name, stdout))
+	if (filename__fprintf_build_id(input_name, stdout) > 0)
 		goto out;
 
 	session = perf_session__new(&file, false, &build_id__mark_dso_hit_ops);
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 105332e..4430340 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1671,6 +1671,11 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
 			    itrace_parse_synth_opts),
 	OPT_BOOLEAN(0, "full-source-path", &srcline_full_filename,
 			"Show full source file name path for source lines"),
+	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
+			"Enable symbol demangling"),
+	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
+			"Enable kernel symbol demangling"),
+
 	OPT_END()
 	};
 	const char * const script_subcommands[] = { "record", "report", NULL };
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 2f1162d..4e3abba 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1,3 +1,21 @@
+/*
+ * builtin-trace.c
+ *
+ * Builtin 'trace' command:
+ *
+ * Display a continuously updated trace of any workload, CPU, specific PID,
+ * system wide, etc.  Default format is loosely strace like, but any other
+ * event may be specified using --event.
+ *
+ * Copyright (C) 2012, 2013, 2014, 2015 Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
+ *
+ * Initially based on the 'trace' prototype by Thomas Gleixner:
+ *
+ * http://lwn.net/Articles/415728/ ("Announcing a new utility: 'trace'")
+ *
+ * Released under the GPL v2. (and only v2, not any later version)
+ */
+
 #include <traceevent/event-parse.h>
 #include "builtin.h"
 #include "util/color.h"
@@ -27,6 +45,7 @@
 
 #ifndef MADV_HWPOISON
 # define MADV_HWPOISON		100
+
 #endif
 
 #ifndef MADV_MERGEABLE
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index b857fcb..07dbff5 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -231,7 +231,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			(*argc)--;
 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
 			perf_debugfs_set_path(cmd + strlen(CMD_DEBUGFS_DIR));
-			fprintf(stderr, "dir: %s\n", debugfs_mountpoint);
+			fprintf(stderr, "dir: %s\n", tracing_path);
 			if (envchanged)
 				*envchanged = 1;
 		} else if (!strcmp(cmd, "--list-cmds")) {
diff --git a/tools/perf/scripts/python/bin/compaction-times-record b/tools/perf/scripts/python/bin/compaction-times-record
new file mode 100644
index 0000000..6edcd40
--- /dev/null
+++ b/tools/perf/scripts/python/bin/compaction-times-record
@@ -0,0 +1,2 @@
+#!/bin/bash
+perf record -e compaction:mm_compaction_begin -e compaction:mm_compaction_end -e compaction:mm_compaction_migratepages -e compaction:mm_compaction_isolate_migratepages -e compaction:mm_compaction_isolate_freepages $@
diff --git a/tools/perf/scripts/python/bin/compaction-times-report b/tools/perf/scripts/python/bin/compaction-times-report
new file mode 100644
index 0000000..3dc1389
--- /dev/null
+++ b/tools/perf/scripts/python/bin/compaction-times-report
@@ -0,0 +1,4 @@
+#!/bin/bash
+#description: display time taken by mm compaction
+#args: [-h] [-u] [-p|-pv] [-t | [-m] [-fs] [-ms]] [pid|pid-range|comm-regex]
+perf script -s "$PERF_EXEC_PATH"/scripts/python/compaction-times.py $@
diff --git a/tools/perf/scripts/python/compaction-times.py b/tools/perf/scripts/python/compaction-times.py
new file mode 100644
index 0000000..239cb05
--- /dev/null
+++ b/tools/perf/scripts/python/compaction-times.py
@@ -0,0 +1,311 @@
+# report time spent in compaction
+# Licensed under the terms of the GNU GPL License version 2
+
+# testing:
+# 'echo 1 > /proc/sys/vm/compact_memory' to force compaction of all zones
+
+import os
+import sys
+import re
+
+import signal
+signal.signal(signal.SIGPIPE, signal.SIG_DFL)
+
+usage = "usage: perf script report compaction-times.py -- [-h] [-u] [-p|-pv] [-t | [-m] [-fs] [-ms]] [pid|pid-range|comm-regex]\n"
+
+class popt:
+	DISP_DFL = 0
+	DISP_PROC = 1
+	DISP_PROC_VERBOSE=2
+
+class topt:
+	DISP_TIME = 0
+	DISP_MIG = 1
+	DISP_ISOLFREE = 2
+	DISP_ISOLMIG = 4
+	DISP_ALL = 7
+
+class comm_filter:
+	def __init__(self, re):
+		self.re = re
+
+	def filter(self, pid, comm):
+		m = self.re.search(comm)
+		return m == None or m.group() == ""
+
+class pid_filter:
+	def __init__(self, low, high):
+		self.low = (0 if low == "" else int(low))
+		self.high = (0 if high == "" else int(high))
+
+	def filter(self, pid, comm):
+		return not (pid >= self.low and (self.high == 0 or pid <= self.high))
+
+def set_type(t):
+	global opt_disp
+	opt_disp = (t if opt_disp == topt.DISP_ALL else opt_disp|t)
+
+def ns(sec, nsec):
+	return (sec * 1000000000) + nsec
+
+def time(ns):
+	return "%dns" % ns if opt_ns else "%dus" % (round(ns, -3) / 1000)
+
+class pair:
+	def __init__(self, aval, bval, alabel = None, blabel = None):
+		self.alabel = alabel
+		self.blabel = blabel
+		self.aval = aval
+		self.bval = bval
+
+	def __add__(self, rhs):
+		self.aval += rhs.aval
+		self.bval += rhs.bval
+		return self
+
+	def __str__(self):
+		return "%s=%d %s=%d" % (self.alabel, self.aval, self.blabel, self.bval)
+
+class cnode:
+	def __init__(self, ns):
+		self.ns = ns
+		self.migrated = pair(0, 0, "moved", "failed")
+		self.fscan = pair(0,0, "scanned", "isolated")
+		self.mscan = pair(0,0, "scanned", "isolated")
+
+	def __add__(self, rhs):
+		self.ns += rhs.ns
+		self.migrated += rhs.migrated
+		self.fscan += rhs.fscan
+		self.mscan += rhs.mscan
+		return self
+
+	def __str__(self):
+		prev = 0
+		s = "%s " % time(self.ns)
+		if (opt_disp & topt.DISP_MIG):
+			s += "migration: %s" % self.migrated
+			prev = 1
+		if (opt_disp & topt.DISP_ISOLFREE):
+			s += "%sfree_scanner: %s" % (" " if prev else "", self.fscan)
+			prev = 1
+		if (opt_disp & topt.DISP_ISOLMIG):
+			s += "%smigration_scanner: %s" % (" " if prev else "", self.mscan)
+		return s
+
+	def complete(self, secs, nsecs):
+		self.ns = ns(secs, nsecs) - self.ns
+
+	def increment(self, migrated, fscan, mscan):
+		if (migrated != None):
+			self.migrated += migrated
+		if (fscan != None):
+			self.fscan += fscan
+		if (mscan != None):
+			self.mscan += mscan
+
+
+class chead:
+	heads = {}
+	val = cnode(0);
+	fobj = None
+
+	@classmethod
+	def add_filter(cls, filter):
+		cls.fobj = filter
+
+	@classmethod
+	def create_pending(cls, pid, comm, start_secs, start_nsecs):
+		filtered = 0
+		try:
+			head = cls.heads[pid]
+			filtered = head.is_filtered()
+		except KeyError:
+			if cls.fobj != None:
+				filtered = cls.fobj.filter(pid, comm)
+			head = cls.heads[pid] = chead(comm, pid, filtered)
+
+		if not filtered:
+			head.mark_pending(start_secs, start_nsecs)
+
+	@classmethod
+	def increment_pending(cls, pid, migrated, fscan, mscan):
+		head = cls.heads[pid]
+		if not head.is_filtered():
+			if head.is_pending():
+				head.do_increment(migrated, fscan, mscan)
+			else:
+				sys.stderr.write("missing start compaction event for pid %d\n" % pid)
+
+	@classmethod
+	def complete_pending(cls, pid, secs, nsecs):
+		head = cls.heads[pid]
+		if not head.is_filtered():
+			if head.is_pending():
+				head.make_complete(secs, nsecs)
+			else:
+				sys.stderr.write("missing start compaction event for pid %d\n" % pid)
+
+	@classmethod
+	def gen(cls):
+		if opt_proc != popt.DISP_DFL:
+			for i in cls.heads:
+				yield cls.heads[i]
+
+	@classmethod
+	def str(cls):
+		return cls.val
+
+	def __init__(self, comm, pid, filtered):
+		self.comm = comm
+		self.pid = pid
+		self.val = cnode(0)
+		self.pending = None
+		self.filtered = filtered
+		self.list = []
+
+	def __add__(self, rhs):
+		self.ns += rhs.ns
+		self.val += rhs.val
+		return self
+
+	def mark_pending(self, secs, nsecs):
+		self.pending = cnode(ns(secs, nsecs))
+
+	def do_increment(self, migrated, fscan, mscan):
+		self.pending.increment(migrated, fscan, mscan)
+
+	def make_complete(self, secs, nsecs):
+		self.pending.complete(secs, nsecs)
+		chead.val += self.pending
+
+		if opt_proc != popt.DISP_DFL:
+			self.val += self.pending
+
+			if opt_proc == popt.DISP_PROC_VERBOSE:
+				self.list.append(self.pending)
+		self.pending = None
+
+	def enumerate(self):
+		if opt_proc == popt.DISP_PROC_VERBOSE and not self.is_filtered():
+			for i, pelem in enumerate(self.list):
+				sys.stdout.write("%d[%s].%d: %s\n" % (self.pid, self.comm, i+1, pelem))
+
+	def is_pending(self):
+		return self.pending != None
+
+	def is_filtered(self):
+		return self.filtered
+
+	def display(self):
+		if not self.is_filtered():
+			sys.stdout.write("%d[%s]: %s\n" % (self.pid, self.comm, self.val))
+
+
+def trace_end():
+	sys.stdout.write("total: %s\n" % chead.str())
+	for i in chead.gen():
+		i.display(),
+		i.enumerate()
+
+def compaction__mm_compaction_migratepages(event_name, context, common_cpu,
+	common_secs, common_nsecs, common_pid, common_comm,
+	common_callchain, nr_migrated, nr_failed):
+
+	chead.increment_pending(common_pid,
+		pair(nr_migrated, nr_failed), None, None)
+
+def compaction__mm_compaction_isolate_freepages(event_name, context, common_cpu,
+        common_secs, common_nsecs, common_pid, common_comm,
+        common_callchain, start_pfn, end_pfn, nr_scanned, nr_taken):
+
+	chead.increment_pending(common_pid,
+		None, pair(nr_scanned, nr_taken), None)
+
+def compaction__mm_compaction_isolate_migratepages(event_name, context, common_cpu,
+        common_secs, common_nsecs, common_pid, common_comm,
+        common_callchain, start_pfn, end_pfn, nr_scanned, nr_taken):
+
+	chead.increment_pending(common_pid,
+		None, None, pair(nr_scanned, nr_taken))
+
+def compaction__mm_compaction_end(event_name, context, common_cpu,
+	common_secs, common_nsecs, common_pid, common_comm,
+	common_callchain, zone_start, migrate_start, free_start, zone_end,
+	sync, status):
+
+	chead.complete_pending(common_pid, common_secs, common_nsecs)
+
+def compaction__mm_compaction_begin(event_name, context, common_cpu,
+	common_secs, common_nsecs, common_pid, common_comm,
+	common_callchain, zone_start, migrate_start, free_start, zone_end,
+	sync):
+
+	chead.create_pending(common_pid, common_comm, common_secs, common_nsecs)
+
+def pr_help():
+	global usage
+
+	sys.stdout.write(usage)
+	sys.stdout.write("\n")
+	sys.stdout.write("-h	display this help\n")
+	sys.stdout.write("-p	display by process\n")
+	sys.stdout.write("-pv	display by process (verbose)\n")
+	sys.stdout.write("-t	display stall times only\n")
+	sys.stdout.write("-m	display stats for migration\n")
+	sys.stdout.write("-fs	display stats for free scanner\n")
+	sys.stdout.write("-ms	display stats for migration scanner\n")
+	sys.stdout.write("-u	display results in microseconds (default nanoseconds)\n")
+
+
+comm_re = None
+pid_re = None
+pid_regex = "^(\d*)-(\d*)$|^(\d*)$"
+
+opt_proc = popt.DISP_DFL
+opt_disp = topt.DISP_ALL
+
+opt_ns = True
+
+argc = len(sys.argv) - 1
+if argc >= 1:
+	pid_re = re.compile(pid_regex)
+
+	for i, opt in enumerate(sys.argv[1:]):
+		if opt[0] == "-":
+			if opt == "-h":
+				pr_help()
+				exit(0);
+			elif opt == "-p":
+				opt_proc = popt.DISP_PROC
+			elif opt == "-pv":
+				opt_proc = popt.DISP_PROC_VERBOSE
+			elif opt == '-u':
+				opt_ns = False
+			elif opt == "-t":
+				set_type(topt.DISP_TIME)
+			elif opt == "-m":
+				set_type(topt.DISP_MIG)
+			elif opt == "-fs":
+				set_type(topt.DISP_ISOLFREE)
+			elif opt == "-ms":
+				set_type(topt.DISP_ISOLMIG)
+			else:
+				sys.exit(usage)
+
+		elif i == argc - 1:
+			m = pid_re.search(opt)
+			if m != None and m.group() != "":
+				if m.group(3) != None:
+					f = pid_filter(m.group(3), m.group(3))
+				else:
+					f = pid_filter(m.group(1), m.group(2))
+			else:
+				try:
+					comm_re=re.compile(opt)
+				except:
+					sys.stderr.write("invalid regex '%s'" % opt)
+					sys.exit(usage)
+				f = comm_filter(comm_re)
+
+			chead.add_filter(f)
diff --git a/tools/perf/ui/browser.h b/tools/perf/ui/browser.h
index 52be871..f3cef56 100644
--- a/tools/perf/ui/browser.h
+++ b/tools/perf/ui/browser.h
@@ -61,8 +61,8 @@ int ui_browser__help_window(struct ui_browser *browser, const char *text);
 bool ui_browser__dialog_yesno(struct ui_browser *browser, const char *text);
 int ui_browser__input_window(const char *title, const char *text, char *input,
 			     const char *exit_msg, int delay_sec);
-struct perf_session_env;
-int tui__header_window(struct perf_session_env *env);
+struct perf_env;
+int tui__header_window(struct perf_env *env);
 
 void ui_browser__argv_seek(struct ui_browser *browser, off_t offset, int whence);
 unsigned int ui_browser__argv_refresh(struct ui_browser *browser);
diff --git a/tools/perf/ui/browsers/header.c b/tools/perf/ui/browsers/header.c
index f106817..edbeaaf 100644
--- a/tools/perf/ui/browsers/header.c
+++ b/tools/perf/ui/browsers/header.c
@@ -91,7 +91,7 @@ static int ui__list_menu(int argc, char * const argv[])
 	return list_menu__run(&menu);
 }
 
-int tui__header_window(struct perf_session_env *env)
+int tui__header_window(struct perf_env *env)
 {
 	int i, argc = 0;
 	char **argv;
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 10c7ec0..cf86f2d 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -26,7 +26,7 @@ struct hist_browser {
 	struct map_symbol   *selection;
 	struct hist_browser_timer *hbt;
 	struct pstack	    *pstack;
-	struct perf_session_env *env;
+	struct perf_env *env;
 	int		     print_seq;
 	bool		     show_dso;
 	bool		     show_headers;
@@ -1214,7 +1214,7 @@ static int hist_browser__dump(struct hist_browser *browser)
 
 static struct hist_browser *hist_browser__new(struct hists *hists,
 					      struct hist_browser_timer *hbt,
-					      struct perf_session_env *env)
+					      struct perf_env *env)
 {
 	struct hist_browser *browser = zalloc(sizeof(*browser));
 
@@ -1695,7 +1695,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 				    bool left_exits,
 				    struct hist_browser_timer *hbt,
 				    float min_pcnt,
-				    struct perf_session_env *env)
+				    struct perf_env *env)
 {
 	struct hists *hists = evsel__hists(evsel);
 	struct hist_browser *browser = hist_browser__new(hists, hbt, env);
@@ -2016,7 +2016,7 @@ struct perf_evsel_menu {
 	struct perf_evsel *selection;
 	bool lost_events, lost_events_warned;
 	float min_pcnt;
-	struct perf_session_env *env;
+	struct perf_env *env;
 };
 
 static void perf_evsel_menu__write(struct ui_browser *browser,
@@ -2169,7 +2169,7 @@ static int __perf_evlist__tui_browse_hists(struct perf_evlist *evlist,
 					   int nr_entries, const char *help,
 					   struct hist_browser_timer *hbt,
 					   float min_pcnt,
-					   struct perf_session_env *env)
+					   struct perf_env *env)
 {
 	struct perf_evsel *pos;
 	struct perf_evsel_menu menu = {
@@ -2202,7 +2202,7 @@ static int __perf_evlist__tui_browse_hists(struct perf_evlist *evlist,
 int perf_evlist__tui_browse_hists(struct perf_evlist *evlist, const char *help,
 				  struct hist_browser_timer *hbt,
 				  float min_pcnt,
-				  struct perf_session_env *env)
+				  struct perf_env *env)
 {
 	int nr_entries = evlist->nr_entries;
 
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 4a2c2f0..d909459 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -93,6 +93,38 @@ int build_id__sprintf(const u8 *build_id, int len, char *bf)
 	return raw - build_id;
 }
 
+int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
+{
+	char notes[PATH_MAX];
+	u8 build_id[BUILD_ID_SIZE];
+	int ret;
+
+	if (!root_dir)
+		root_dir = "";
+
+	scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
+
+	ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
+	if (ret < 0)
+		return ret;
+
+	return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
+}
+
+int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
+{
+	u8 build_id[BUILD_ID_SIZE];
+	int ret;
+
+	ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
+	if (ret < 0)
+		return ret;
+	else if (ret != sizeof(build_id))
+		return -EINVAL;
+
+	return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
+}
+
 /* asnprintf consolidates asprintf and snprintf */
 static int asnprintf(char **strp, size_t size, const char *fmt, ...)
 {
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index ce2f493..27a14a8 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -12,6 +12,9 @@ extern struct perf_tool build_id__mark_dso_hit_ops;
 struct dso;
 
 int build_id__sprintf(const u8 *build_id, int len, char *bf);
+int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id);
+int filename__sprintf_build_id(const char *pathname, char *sbuild_id);
+
 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size);
 
 int build_id__mark_dso_hit(struct perf_tool *tool, union perf_event *event,
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index e9a5d43..8d00039 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -98,6 +98,7 @@ static void perf_evlist__purge(struct perf_evlist *evlist)
 
 	evlist__for_each_safe(evlist, n, pos) {
 		list_del_init(&pos->node);
+		pos->evlist = NULL;
 		perf_evsel__delete(pos);
 	}
 
@@ -125,6 +126,7 @@ void perf_evlist__delete(struct perf_evlist *evlist)
 
 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
 {
+	entry->evlist = evlist;
 	list_add_tail(&entry->node, &evlist->entries);
 	entry->idx = evlist->nr_entries;
 	entry->tracking = !entry->idx;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 436e358..b39a619 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -56,6 +56,7 @@ struct perf_evlist {
 	struct cpu_map	  *cpus;
 	struct perf_evsel *selected;
 	struct events_stats stats;
+	struct perf_env	*env;
 };
 
 struct perf_evsel_str_handler {
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index b096ef7..bac25f4 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -206,6 +206,7 @@ void perf_evsel__init(struct perf_evsel *evsel,
 	evsel->leader	   = evsel;
 	evsel->unit	   = "";
 	evsel->scale	   = 1.0;
+	evsel->evlist	   = NULL;
 	INIT_LIST_HEAD(&evsel->node);
 	INIT_LIST_HEAD(&evsel->config_terms);
 	perf_evsel__object.init(evsel);
@@ -1026,6 +1027,7 @@ void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
 void perf_evsel__exit(struct perf_evsel *evsel)
 {
 	assert(list_empty(&evsel->node));
+	assert(evsel->evlist == NULL);
 	perf_evsel__free_fd(evsel);
 	perf_evsel__free_id(evsel);
 	perf_evsel__free_config_terms(evsel);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 93ac6b1..298e6bb 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -60,6 +60,9 @@ struct perf_evsel_config_term {
 
 /** struct perf_evsel - event selector
  *
+ * @evlist - evlist this evsel is in, if it is in one.
+ * @node - To insert it into evlist->entries or in other list_heads, say in
+ *         the event parsing routines.
  * @name - Can be set to retain the original event name passed by the user,
  *         so that when showing results in tools such as 'perf stat', we
  *         show the name used, not some alias.
@@ -73,6 +76,7 @@ struct perf_evsel_config_term {
  */
 struct perf_evsel {
 	struct list_head	node;
+	struct perf_evlist	*evlist;
 	struct perf_event_attr	attr;
 	char			*filter;
 	struct xyarray		*fd;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 179b2bd..4181454 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2514,6 +2514,7 @@ int perf_session__read_header(struct perf_session *session)
 	if (session->evlist == NULL)
 		return -ENOMEM;
 
+	session->evlist->env = &header->env;
 	if (perf_data_file__is_pipe(file))
 		return perf_header__read_pipe(session);
 
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 9b53b65..396e496 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -66,7 +66,7 @@ struct perf_header;
 int perf_file_header__read(struct perf_file_header *header,
 			   struct perf_header *ph, int fd);
 
-struct perf_session_env {
+struct perf_env {
 	char			*hostname;
 	char			*os_release;
 	char			*version;
@@ -98,7 +98,7 @@ struct perf_header {
 	u64				data_size;
 	u64				feat_offset;
 	DECLARE_BITMAP(adds_features, HEADER_FEAT_BITS);
-	struct perf_session_env 	env;
+	struct perf_env 	env;
 };
 
 struct perf_evlist;
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index bc528d5..de6d58e 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -313,7 +313,7 @@ int hist_entry__tui_annotate(struct hist_entry *he, struct perf_evsel *evsel,
 int perf_evlist__tui_browse_hists(struct perf_evlist *evlist, const char *help,
 				  struct hist_browser_timer *hbt,
 				  float min_pcnt,
-				  struct perf_session_env *env);
+				  struct perf_env *env);
 int script_browse(const char *script_opt);
 #else
 static inline
@@ -321,7 +321,7 @@ int perf_evlist__tui_browse_hists(struct perf_evlist *evlist __maybe_unused,
 				  const char *help __maybe_unused,
 				  struct hist_browser_timer *hbt __maybe_unused,
 				  float min_pcnt __maybe_unused,
-				  struct perf_session_env *env __maybe_unused)
+				  struct perf_env *env __maybe_unused)
 {
 	return 0;
 }
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 18722e7..8a4537e 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -170,7 +170,7 @@ static void perf_session__delete_threads(struct perf_session *session)
 	machine__delete_threads(&session->machines.host);
 }
 
-static void perf_session_env__exit(struct perf_session_env *env)
+static void perf_session_env__exit(struct perf_env *env)
 {
 	zfree(&env->hostname);
 	zfree(&env->os_release);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 46ae053..1f97ffb 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1853,7 +1853,7 @@ static void vmlinux_path__exit(void)
 	zfree(&vmlinux_path);
 }
 
-static int vmlinux_path__init(struct perf_session_env *env)
+static int vmlinux_path__init(struct perf_env *env)
 {
 	struct utsname uts;
 	char bf[PATH_MAX];
@@ -1964,7 +1964,7 @@ static bool symbol__read_kptr_restrict(void)
 	return value;
 }
 
-int symbol__init(struct perf_session_env *env)
+int symbol__init(struct perf_env *env)
 {
 	const char *symfs;
 
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index a4cde92..440ba8a 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -252,8 +252,8 @@ int modules__parse(const char *filename, void *arg,
 int filename__read_debuglink(const char *filename, char *debuglink,
 			     size_t size);
 
-struct perf_session_env;
-int symbol__init(struct perf_session_env *env);
+struct perf_env;
+int symbol__init(struct perf_env *env);
 void symbol__exit(void);
 void symbol__elf_init(void);
 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name);
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index f7adf12..7acafb3 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -34,6 +34,7 @@ bool test_attr__enabled;
 bool perf_host  = true;
 bool perf_guest = false;
 
+char tracing_path[PATH_MAX + 1]        = "/sys/kernel/debug/tracing";
 char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";
 
 void event_attr_init(struct perf_event_attr *attr)
@@ -391,6 +392,8 @@ void set_term_quiet_input(struct termios *old)
 
 static void set_tracing_events_path(const char *tracing, const char *mountpoint)
 {
+	snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
+		 mountpoint, tracing);
 	snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
 		 mountpoint, tracing, "events");
 }
@@ -436,66 +439,14 @@ const char *perf_debugfs_mount(const char *mountpoint)
 
 void perf_debugfs_set_path(const char *mntpt)
 {
-	snprintf(debugfs_mountpoint, strlen(debugfs_mountpoint), "%s", mntpt);
 	set_tracing_events_path("tracing/", mntpt);
 }
 
-static const char *find_tracefs(void)
-{
-	const char *path = __perf_tracefs_mount(NULL);
-
-	return path;
-}
-
-static const char *find_debugfs(void)
-{
-	const char *path = __perf_debugfs_mount(NULL);
-
-	if (!path)
-		fprintf(stderr, "Your kernel does not support the debugfs filesystem");
-
-	return path;
-}
-
-/*
- * Finds the path to the debugfs/tracing
- * Allocates the string and stores it.
- */
-const char *find_tracing_dir(void)
-{
-	const char *tracing_dir = "";
-	static char *tracing;
-	static int tracing_found;
-	const char *debugfs;
-
-	if (tracing_found)
-		return tracing;
-
-	debugfs = find_tracefs();
-	if (!debugfs) {
-		tracing_dir = "/tracing";
-		debugfs = find_debugfs();
-		if (!debugfs)
-			return NULL;
-	}
-
-	if (asprintf(&tracing, "%s%s", debugfs, tracing_dir) < 0)
-		return NULL;
-
-	tracing_found = 1;
-	return tracing;
-}
-
 char *get_tracing_file(const char *name)
 {
-	const char *tracing;
 	char *file;
 
-	tracing = find_tracing_dir();
-	if (!tracing)
-		return NULL;
-
-	if (asprintf(&file, "%s/%s", tracing, name) < 0)
+	if (asprintf(&file, "%s/%s", tracing_path, name) < 0)
 		return NULL;
 
 	return file;
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 88a8915..291be1d 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -83,10 +83,10 @@
 extern const char *graph_line;
 extern const char *graph_dotted_line;
 extern char buildid_dir[];
+extern char tracing_path[];
 extern char tracing_events_path[];
 extern void perf_debugfs_set_path(const char *mountpoint);
 const char *perf_debugfs_mount(const char *mountpoint);
-const char *find_tracing_dir(void);
 char *get_tracing_file(const char *name);
 void put_tracing_file(char *file);